public async Task SubscribeThrows()
{
var client = new AggregateTradeWebSocketClient(new Mock <IWebSocketClient>().Object);
await Assert.ThrowsAsync <ArgumentNullException>("symbol", () => client.SubscribeAsync(null, new CancellationToken()));
await Assert.ThrowsAsync <ArgumentException>("token", () => client.SubscribeAsync(Symbol.BTC_USDT, CancellationToken.None));
}